Many of the commonly used antimicrobial agents are synthetic compounds. In recent years, there has been an increased interest in avoiding or eliminating the use of synthetic compounds and in developing and promoting the use of natural materials. Consumers generally consider plant materials less toxic and a more suitable natural alternative to synthetic compounds.
Various herbal and plant preparations are known for certain uses. For example, Listerine® antiseptic mouthwash is a known composition containing thyme oil, eucalyptus oil, methyl salicylate (wintergreen oil), and menthol in an alcohol solution. This composition is produced as an oral hygiene composition. Various reports have been produced showing Listerine® causes a reduction in plaque and gingivitis. Although various other plant compositions have been produced, many of the commercially available compositions have not shown substantial antimicrobial activity.
The body normally serves as host for a variety of bacteria and fungi. Most of the time, the balance between the body as host and the microorganisms is maintained. Sometimes, however, conditions exist that permit the microorganisms to tip that balance, causing an infection. Such fungi are only problematic when they grow in an uncontrolled manner, causing various diseases as well as discomfort for the infected human or animal. Unfortunately, uncontrolled fungal growths regularly occur, making topical anti-fungal preparations one of the largest segments of the market for topical external products.
Once fungal populations have become uncontrolled, the resultant infection is difficult to treat successfully. Synthetic topical antifungal preparations are commonly used for treatment. However, such infections are often recurrent and require a prolonged treatment regimen. Some consumers find prolonged treatment using synthetic products undesirable.
Certain fungal infections of the skin known as tinea infections are caused by dermatophytes, which are members of the Trichophyton, Microsporum and Epidermophyton species. These mold-like fungi thrive in warm, moist areas, thriving on the dead tissues of hair, nails, and outer skin layers. Tinea infections include tinea pedis, known as athlete's foot; tinea corporis, known as ringworm; tinea capitis, a fungal infection of the scalp that can cause hair loss; tinea cruris, known as jock itch or tinea of the groin; tinea unguum, which is tinea of the nails; and tinea versicolor, a superficial fungal infection that produces brown, tan, or white spots on the trunk of the body. Tinea infections are contagious and can be passed through direct contact or by contact with clothing, from shower and pool surfaces, and even from pets.
Athlete's foot or tinea pedis is by far the most common form, with more than 12 million people in the United States suffering from the disease per year. It presents with redness, itching, burning, cracking, scaling, swelling and occasionally bleeding. The condition generally includes small vesicles, fissures, scaling, maceration, hyperkeratinization, and eroded areas between the toes and on the plantar surface of the foot, as well as on other skin areas. The nails may show thickening, pitting and subungal debris. Local antifungals include imidazoles, such as miconazole nitrate and clotrimazole, tolnaftate, and terbinafine hydrochloride. The common fungicidal and fungistatic chemical treatments frequently fail to contact the fungi in the horny layers of the skin, which means athlete's foot slowly clears with local antifungal therapy or systemic antifungals. This requires the infected individual to take treatments for considerable lengths of time, potentially for months. Common treatments for athlete's foot using local antifungals require treatment two or three times a day for at least 7 to 14 days, and for some medications, for up to four weeks. It is common treatment to apply the topical antifungal for two weeks after the skin is healed, to eradicate all remaining fungal spores. Physicians commonly prescribe medications in the form of powders, aerosols, liquids or creams for the treatment of tinea pedis.
However, reoccurrences of the infection are frequent. For some patients, such as those also afflicted with diabetes or circulatory problems, tinea infections and their treatment can be quite serious. The source of the affliction often is a public safety and health concern, as the occurrence of tinea pedis is higher in public areas such as locker rooms, public showers, sports facilities, and the like.
Increasingly, herbal remedies are sought due to concerns caused by antibiotic-resistant and other drug-resistant infectious agents. Even with herbal treatments, however, numerous difficulties are encountered in the treatment of medical conditions. A single herb may contain numerous active, and sometimes conflicting, components. The common herb, rhubarb, for example, may be used in small doses for treating constipation due to its tannic acid component, but is a potent laxative in larger doses because of other components. Other herbs, such as black walnut extract, which may be used to treat athlete's foot and related fungal infections, can be toxic if taken inappropriately. In addition to those difficulties mentioned in connection with single herbs, combinations raise the possibility of deleterious effects among components in the various herbs, and increase the difficulties associated with anticipating and analyzing side effects.